Angle Closure Glaucoma



Angle Closure Glaucoma


Sandra Fernando Sieminski

Sanjay Mohan



THE CLINICAL CHALLENGE

Angle closure is a process that results from appositional closure of the iridocorneal angle, or drainage angle of the eye, leading to aqueous humor outflow obstruction and consequent increase in intraocular pressure (IOP). This increase in IOP can lead to progressive optic nerve damage and peripheral vision loss, which is a disease state known as glaucoma. Primary angle-closure (PAC) occurs when obstruction is a result of anatomic predisposition of the eye to have crowding of the angle, usually owing to a small eye or a large cataract. Secondary angle-closure is attributable to a coexisting ocular disease process (eg, inflammation, tumor, or hemorrhage), which causes physical occlusion of the angle owing to debris or scar tissue formation in the angle. In the United States, although more than 80% of glaucoma cases are open-angle in etiology, angle closure glaucoma accounts for a disproportionate number of patients with severe vision loss and thus accounts for more emergency department (ED) visits.1

The prevalence of angle closure glaucoma varies considerably among ethnic and racial groups. Inuit and Asian populations account for the highest rates, whereas lower rates are reported in African and European populations.2 Other risk factors include female gender, farsightedness (hyperopia), having a shallow anterior chamber, use of medications that can induce angle narrowing (eg, pupil dilators, including alpha agonists and anticholinergic agents), advanced age (most common between ages of 55 and 65), cataracts, and family history.2

The challenge of this disease primarily posits in prevention and diagnosis. Much like open-angle glaucoma, closed-angle glaucoma is typically an asymptomatic disease process in which patients are unaware of this illness until advanced visual loss occurs. Whereas acute angle closure glaucoma presents with a change in vision or with severe acute symptoms, chronic angle closure glaucoma tends to be discovered incidentally.

Clinical presentation and symptoms result from the rapidity and degree of IOP elevation. Acute angle glaucoma is suggested by severe ocular or periocular pain, decreased vision, halos around lights, headache, nausea, and vomiting. In contrast, chronic angle glaucoma patients are asymptomatic because the rise in IOP is gradual and less severe.





APPROACH/THE FOCUSED EXAM

In approaching a patient with suspected angle closure, it is important to elicit a thorough history. This includes history of eye surgery, medications, recent medical procedures, recent facial trauma, contact lens use, eye drop use, and prior occurrences of eye pain and/or redness. Patients may endorse symptoms such as halos around lights, blurry vision, headache over the brow, and nausea. Their symptom onset can be linked to starting a new medication or entering a dimly lit room, which causes pupillary dilation.4

As with any ocular pathology, visual acuity should be assessed. Given the degree of pain and discomfort, the patient may be unable to read letters on a Snellen chart, and if so, it should be determined whether the patient can count fingers or perceive hand movements or light. On gross inspection, the patient will classically present with a unilateral red eye, a fixed mid-dilated pupil, and some degree of corneal clouding secondary to edema.4 There can also be focal redness surrounding the limbus (the junction between the cornea and the sclera), pigment granules or white flecks on the anterior surface of the cataract, iris atrophy or transillumination caused by iris ischemia from high IOP if this is not the patient’s first episode of angle closure, and a shallow anterior chamber (the space between the cornea and the iris). Many of these features are seen in Figure 47.2 of a patient presenting in angle closure after receiving laser iridotomy.

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Apr 18, 2023 | Posted by in OTOLARYNGOLOGY | Comments Off on Angle Closure Glaucoma

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